Must be because of the zombie pandemic; the invisible anti-logic bounce altering waves they emit disrupt the normal bounce physics of breasts and thus cause them to bounce and jiggle at the slightest movement.

Yeah, but it usually requires a little bit more brain activity than that of a zombie.Even blind people usually have to practice, but the zombies can from the very start apparently know instantly where every part of you is, even if you meters away from them.